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| author | Hugh Dickins <hughd@google.com> | 2021-06-24 18:39:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-24 19:40:53 -0700 |
| commit | a7a69d8ba88d8dcee7ef00e91d413a4bd003a814 (patch) | |
| tree | 31e5fe7533a654e098d37c62bd508bca14dc49af | |
| parent | a9a7504d9beaf395481faa91e70e2fd08f7a3dde (diff) | |
| download | linux-a7a69d8ba88d8dcee7ef00e91d413a4bd003a814.tar.gz linux-a7a69d8ba88d8dcee7ef00e91d413a4bd003a814.tar.xz | |
mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk()
Aha! Shouldn't that quick scan over pte_none()s make sure that it holds
ptlock in the PVMW_SYNC case? That too might have been responsible for
BUGs or WARNs in split_huge_page_to_list() or its unmap_page(), though
I've never seen any.
Link: https://lkml.kernel.org/r/1bdf384c-8137-a149-2a1e-475a4791c3c@google.com
Link: https://lore.kernel.org/linux-mm/20210412180659.B9E3.409509F4@e16-tech.com/
Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Wang Yugui <wangyugui@e16-tech.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/page_vma_mapped.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index a4e962b510c7..a4435311754b 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -276,6 +276,10 @@ next_pte: goto restart; } pvmw->pte++; + if ((pvmw->flags & PVMW_SYNC) && !pvmw->ptl) { + pvmw->ptl = pte_lockptr(mm, pvmw->pmd); + spin_lock(pvmw->ptl); + } } while (pte_none(*pvmw->pte)); if (!pvmw->ptl) { |